[Code of Federal Regulations]
[Title 49, Volume 2]
[Revised as of October 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR179.100-8]

[Page 1009]
 
                        TITLE 49--TRANSPORTATION
 
 CHAPTER I--RESEARCH AND SPECIAL PROGRAMS ADMINISTRATION, DEPARTMENT OF 
                             TRANSPORTATION
 
PART 179_SPECIFICATIONS FOR TANK CARS--Table of Contents
 
 Subpart C_Specifications for Pressure Tank Car Tanks (Classes DOT-105, 
                         109, 112, 114 and 120)
 
Sec.  179.100-8  Tank heads.

    (a) The tank head shape shall be an ellipsoid of revolution in which 
the major axis shall equal the diameter of the shell adjacent to the 
head and the minor axis shall be one-half the major axis.
    (b) Each tank head made from steel which is required to be ``fine 
grain'' by the material specification, which is hot formed at a 
temperature exceeding 1700 [deg]F., must be normalized after forming by 
heating to a temperature between 1550[deg] and 1700 [deg]F., by holding 
at that temperature for at least 1 hour per inch of thickness (30-minute 
minimum), and then by cooling in air. If the material specification 
requires quenching and tempering, the treatment specified in that 
specification must be used instead of the one specified above.

[29 FR 18995, Dec. 29, 1964. Redesignated, 32 FR 5606, Apr. 5, 1967 and 
amended by Amdt. 179-12, 39 FR 15038, Apr. 30, 1974]